There's a HUGE difference between what i assume is a heavy barreled 308win shooting 168 grain bullets and a hunting rifle (likely not a heavy barrel) in 300 winmag shooting 180 grain projectiles. His WILL NOT have the same result. I can practically guarantee it. The ammo he is running is not match ammo. I'd say a 2"group is as good as its going to get for a sporter barrel and non match/hand loaded ammo.
On a side note. Good on your grandson with that group!
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